Lewis & Short

in-vălĕo, ēre, to be strong against, to prevail (late Lat.; vique valebunt is the true reading, Lucr. 2, 301; v. Lachm. ad h. l.; and the perf. invaluit belongs to invalesco; v. the foll. art.): egredi conatus, invalente morbi gravitate detentus est, Amm. 21, 15, 2.